Red cell aplasia and osteoblastic metastases in a patient with thymoma

A case is reported of transient red cell aplasia in a patient with metastatic thymoma. A 32-year-old Caucasian man who was treated with x-ray therapy to the thymus in childhood had a thymoma removed at age 28. Two years later, metastatic nodules were found in the lungs. He was started on therapy with monthly injections of nitrogen mustard. Eleven months later, and one month after his last dose of nitrogen mustard, he developed severe anemia associated with absent red cell precursors in the marrow. Concomitantly, he was discovered to have scattered osteoblastic bone lesions proven by biopsy to be secondary to metastatic uiymoma. The additional findings of lymphopenia, transient anergy, and a basal cell carcinoma of the skin support the contention that impairment of the thymus-dependent immune system was present.